Meso Scale Diagnostic's electrochemiluminescence (ECl) detection technology will be applied to the development of quantitative and highly multiplexed assays for cancer biomarkers. Assays will'be carried out using ECl based detection in an array-based multiplexed format on a fully automated high-throughput immunoassay instrument. This platform will be able to simultaneously measure up to 75 biomarkers using only 30 ul of sample (serum, plasma, ductal lavage, saliva, and urine), will have ultra-sensitive detection capabilities (analytical sensitivity <1 pg/ml), a dynamic range of 8-logs, and a throughput of 100 to 200 samples per day. As part of the proposed program, 50 cancer associated biomarker assays will be developed for this assay platform. When selecting assays focus will be on biomarkers that have been identified by the Clinical Proteomics Technologies for Cancer (CPTC) initiative and CPTC investigators, giving highest priority to biomarkers for which CPTC is developing antibodies. Assay reagents for running the cancer biomarker panels will be provided in a complete consumable kit that will include a 96-well assay plate containing up to 25 immobilized capture antibodies per well (larger assay panels are achieved by spreading the arrays of capture antibodies over multiple wells), and an auxiliary reagent plate containing Iyopholized detection antibodies and assay diluents. The assay platform will enable the measurement of numerous cancer associated proteins, and will provide an important tool for the selection and validation of cancer-specific diagnostic biomarkers.